How often do we thank God for his kindness? Not often enough. I mean God is the example to follow..."he is kind to people who are ungrateful and full of sin" Luke 6:35.
In the Greek...kindness carries an added idea the English word doesn't. It refers to an act of grace. It also refers to a deed or person who is "useful, serviceable, and adapted to its purpose." Kindness was even employed to describe food that was tasty as well as healthy. So a salad can be kind.
The usage makes sense, Isn't kindness good and good for you? Pleasant and practical? Kindness not only says good morning, it makes the coffee.